Receiver and housing assembly for a firearm



H. D. ALLYN RECEIVER AND HOUSING ASSEMBLY FOR A FIREARM Dec. 24, 1968 6 Sheets-Sheet 1 Original Filed Sept. 9, 1965 mdE INVENTOR. HAROLD D. ALLYN ATTORNEY.

Dec. 24, 1968 H. D. ALLYN 3,417,499

RECEIVER AND HOUSING ASSEMBLY FOR A FIREARM Original Filed Sept. 9, 1965 6 Sheets-Sheet 3 222 FIG. l9.

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H. D. ALLYN 3,417,499

RECEIVER AND HOUSING ASSEMBLY FOR A FIREARM Dec. 24, 1968 6 Sheets-Sheet 4 Original Filed Sept. 9, 1965 INVENTOR. HAROLD D. ALLYN ATTORNEY.

H. D. ALLYN 3,417,499

RECEIVER AND HOUSING ASSEMBLY FOR A FIREARM Dec. 24, 1968 6 Sheets-Sheet 5 SEE 0mm 1 Qvdrm INVENTOR. HAROLD o. ALLYN M 0mm l mr. 4 9

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Dec. 24, 1968 H. D. ALLYN 3,417,499

RECEIVER AND HOUSING ASSEMBLY FOR A FIREARM original Filed Sept. 9, 1965 s Sheets-Sheet e HAROLD D. ALLYN ATTORNEY.

United States Patent 3,417,499 RECEIVER AND HUUSING ASSEMBLY FOR A FIREARM Harold I). Allyn, 10 Sumner Ave., Springfield, Mass. 01108 Original application Sept. 9, 1965, Ser. No. 485,990, now

Patent No. 3,336,691, dated Aug. 22, 1967. Divided and this application Aug. 14, 1967, Ser. No. 660,522

7 Claims. (CI. 42-75) ABSTRACT 01* THE DISCLOSURE A firearm having a combination of: a barrel, a stock, a receiver, a cam surface on the receiver, a trigger housing, a cam surface on the trigger housing, a magazine housing, a rear bedding screw having a cam surface, and a cam surface on the magazine housing, the trigger housing and magazine housing being held in locked relationship with each other and with the receiver upon the tightening of the rear bedding screw against the cam surface of the trigger housing for effecting a simultaneous tightening of the cam surface on the magazine housing against the cam surface on the receiver.

Cross references to related application This application is a division of application Ser. No. 485,990, filed Sept. 9, 1965, now Patent 3,336,691.

Background of the invention (1) Field of the invention.The fields of art to which the invention pertain to the structures and assembly into interlocking relationship of receiver, magazine housing and trigger housing components of a firearm.

(2) Description of the prior art-References to specific prior art follows: 904,646, Prinke, 11/1908; 976,122, Clement, 11/1910; 1,024,989, Gruver, 4/1912; 1,628,798, Nelson, /1927; 1,572,450, Swe'bilius, 2/1926; 2,945,423, Allyn, 7/1960.

Summary of the invention A new conception of construction is provided, particularly as respects the hammer, trigger, sear, safety, housings and magazine catch, which components require only a pair of pins and a trio of springs to assure ready assemblage and disassemblage.

To particularize, the safety provides a greater-thannormal margin of protection against accidental discharge, when compared with any other sporting firearm of the type incorporating a safety functioning to block a trigger.

Safety traverse, from Fire to Safe positions, realizes a concomitant withdrawal of the sear notch of the hammer from its contact with the point of the interengageable scar and a locking of the hammer against forward movement in that withdrawn position, so that, therefollowing, even should the trigger be pulled, hammer fall and, accordingly, weapon firing are precluded. If the trigger is inadvertently held rearwardly, during any throw of the safety from Safe to Fire positions, hammer fall is precluded. To effect firearm discharge, the trigger must be allowed to move to its forwardmost position before the rearward pulling thereof.

In disassembly, mere removal of the front and rear bedding screws will allow the removal of the barrel-receiver and trigger housing assemblies from the stock, whereafter all components may be readily dismounted without need for further tools, except as respects the removal of the barrel from the receiver and the butt plate from the stock. Reversely, in assembly, after placement of the assemblies into the stock, and while tightening the rear bedding screw, a double camming and locking device,

Patented Dec. 24, 1968 V cone-shaped head on the rear bedding screw so as to cam the trigger housing assembly forwardly and to simultaneously solidly lock the trigger housing assembly and the magazine housing assembly relative to each other and both assemblies relative to the barrel-receiver assembly and the stock.

Brief description of the drawings FIG. 1 is a broken view, in side elevation, of the firearm;

FIG. 2 is a fragmentary view, in top plan, of the breech portion, with the action in closed position;

FIG. 3 is a view, in section, on line 3-3 of FIG. 43;

FIG. 4 is a view, in section, on line 4-4 of FIG. 43;

FIGS. 5 and 6 are views, in rear and side elevation respectively, of the magazine shell;

FIG. 7 is a fragmentary view, in side elevation, with certain parts in section, of the operating mechanism and showing the action in closed position and the magazine omitted;

FIG. 8 is a view, similar to FIG. 7, showing the action in opened position, the hammer in cocked position, the trigger in rearward position, the trigger-sear pin in position at the top of its sear slot, and the magazine in place;

FIG. 9 is a view, similar to FIG. 7, showing the hammer in fired position, the trigger in rearward position, and the trigger-sear pin in position at the top of its sear slot;

FIG. 10 is a view, in top plan, of the firing mechanism shown in FIG. 9, showing the safety in Fire position;

FIG. 11 is a view, similar to FIG. 9, showing the hammer in cocked position, the trigger in forward position, the safety in Safe position, the hammer notch withdrawn from contact with the sear point, and the trigger-sear pin in position at the top of its sear slot;

FIGS. 12 and 13 are views, in top plan and side elevation respectively, of the safety;

FIG. 14 is a view, in section, on line 14-14 of FIG. 10;

FIGS. 15 and 16 are views, in side and front elevation respectively, of the locking bolt;

FIG. 17 is a view, in section, on line 17-17 of FIG. 8;

FIG. 18 is a view, in section, on line 18-18 of FIG. 8;

FIG. 19 is a view, in section, on line ]l919 of FIG. 7;

FIG. 20 is a view, in section, on line 2020 of FIG. 8;

FIGS. 21-24 are views, in top plan, rear elevation, side elevation, and front elevation respectively, of the magazine housing;

FIGS. 25-27 are views, in top plan, side elevation, and front elevation respectively, of the trigger housing;

FIG. 28 is a view, in section, on line 2828 of FIG. 9;

FIG. 29 is a view, in section, on line 29-29 of FIG. 11;

FIGS. 30-31 are views, in side and front elevation respectively, of the magazine catch;

FIG. 32 is a view, in rear elevation, showing the right hand portion of the slide block with the lower portion of the operating handle in place;

FIG. 33 is a view, in side elevation, of the right hand portion of the slide block;

FIG. 34 is a view, in bottom plan, of the right hand portion of the slide block with the lower portion of the operating handle omitted;

FIG. 35 is a view, in side elevation, of the breech bolt and related parts;

FIG. 36 is a view, in top plan, of the breech bolt, with the locking bolt omitted;

FIG. 37 is a view, in front elevation, of the assembled breech bolt, with the locking bolt omitted;

FIG. 38 is a view, in section, on line 3838 of FIG. 36;

FIG. 49 is an exploded view, in perspective, of the barrel-receiver assembly;

FIG. 50 is a view, in perspective, of the trigger-sear spring; and

FIG. 51 is a view, in side elevation, of the rear insert prior to the permanent assembly thereof with the receiver.

Descriptions of the preferred embodiments The firearm includes a stock 2, stock butt 4, fore end cover 6, barrel 8, receiver 10 and locking plate 12.

Receiver 10 is preferentially formed from a stamping and is of inverted U-shape, as will be appreciated by reference to FIG. 49 wherein is shown a rear insert 14 associated therewith as by welding, soldering or brazing thereto.

In assembly, a front insert 16 is positioned within, and locking plate 12 is positioned adjacent, the forward portion of receiver 10. Barrel 8 is extended through a barrel opening 18 in the locking plate for threaded engagement with the front insert so that a rearwardlyfacing end face of an annular barrel shoulder 20, extending radially outwardly of the barrel, is pulled into confrontation with a forwardly-facing face of the locking plate and so that the front insert in concomitantly pulled forwardly wherefore the forwardly-facing faces of lugs 22, extending outwardly of the front insert, contact complemental rearwardly-facing faces of lugs 24 defined by cuts provided in the receiver interior, as best observed in FIGS. 1 and 8.

What is identified as the barrel-receiver assembly includes barrel 8 (which will be subsequently observed to include a cylinder block 266), receiver 10 (including rear insert 14 which is permanently attached to and part of the receiver), and locking plate 12. These components preferentially will be factory-assembled so as not to be detachable by the owner.

Continued reference to FIG. 49 will disclose that, upon assembly, simultaneously with the above, a rearwardlyextending locking plate hook 26 integral with looking plate 12 engages in a complemental cut in the top of the forwardly-facing end face of receiver 10' for assisting in the locking of front insert 16 against relative vertical displacement and of locking plate 12 against radial displacement and in mounting barrel 8 in situ, all with respect to the receiver.

Conceivably, similarly configured locking plate hooks could also be provided on the locking plate side walls for engagement in corresponding complemental cuts in the receiver to insure against any outward spreading of the receiver walls, particularly in the lowermost regions.

A breech bolt 28 (shown in FIGS. 7, 19, 35, 36, 37 and 38, has strategically-located slots 29 in its midsection serving to accommodate a locking bolt 30 (FIGS. and 16) of inverted U-shape having an outwardlyextending cam ear 32 on each of the opposite sides thereof. With the locking bolt assembled in the breech bolt, and during the rearward reciprocation of a bifurcated slide block 34 (FIG. 7), such locking bolt cam ears 32 engage in respective complemental cam cuts provided in the slide block for locking and unlocking the breech bolt and effecting its rearward and forward rectilinear motivation. Inadvertently omit the locking bolt from the assembly and the breech bolt would be precluded from closing upon a live cartridge by reason of the absence of the camming lugs such as are normally contacted by the slide block during the breech bolt opening and closing and locking movements.

Rearward reciprocation of the slide block serves to move locking bolt 30 downwardly and out of locked position as the action is being opened.

As a locking portion of the locking bolt moves out of position within a suitable locking bolt slot 38 in the receiver upper wall, the slide block is enabled to move the locking bolt rearwardly, carrying the breech bolt therewith, and a rear undercut surface 40 of the locking bolt (FIGS. 15 and 35) contacts a cam surface of a firing pin 42 causing the firing pin to be withdrawn rearwardly to a rearward position where the point of the firing pin is precluded from contacting the primer of a cartridge C until the firearm is once again fully closed and the locking bolt has assumed its uppermost and locked position, all whereby positive firing pin withdrawal is achieved.

The firing pin is retained in position by a firing pin retaining pin 44 which is fitted in the upper rear portion of breech bolt 28 and the firing pin retaining pin is precluded from lateral movements by the inside surfaces of slide block 34.

The breech bolt is shown as of one piece but may be of two-part construction comprising a forward portion of a high tensile-strength steel, including the walls of locking bolt slots 29, and a rearward portion of an aluminum casting, the parts being secured together in any known manner. Such a two-part construction would permit achievement of a significant reduction in breech bolt weight.

A plunger-type ejector 48 (FIGS. 36 and 37), actuated by an ejector spring 50, is held by an ejector retaining pin 52 fitted in the breech bolt. Vertical movement of the ejector retaining pin is precluded in that its ends contact the inner top wall of the receiver and inwardly-extending shelves 54 on the slide block (FIG. 19).

The ejector is maintained in a forward position by the ejector spring, and, additional to its regular function, also serves to keep the cartridge head from entering the rim cut in the breech bolt and thus from being contacted by the firing pin, should the breech bolt assume a semi-closed position without the locking bolt being in place.

As seen in FIGS. 35, 36, 37, 39, 40 and 41, an extractor 56 is provided with an extractor hook 58 which is adapted to slide freely within an appropriate cut in the face of breech bolt 28. A main body 60 of the extractor fits freely in an extractor body slot in the breech bolt and a cylinder body 62 of the extractor slides in an appropriate extractor opening.

A semi-circular cut 64 in the outer free end of the cylinder body defines a clearance for the front end of firing pin 42.

A groove 66 in main body 60 receives the front end of an L-shaped extractor spring 70, the rear end thereof resting in a rearwardly-extending portion of the extractor body slot in the breech bolt and passing loosely through a laterally-extending extractor spring opening in the breech bolt. The extractor spring is retained in place by an extractor spring hook 72 and its inherent spring tension retains the hook in a counterbore of the extractor spring opening.

When the slide block is moved rearwardly from closed position by manual or gas operation as the case may be, slide block forward cam cuts 75 contact locking bolt cam ears 32. When the locking portion of the locking bolt is withdrawn from receiver locking bolt slot 38, the breech bolt is moved rearwardly therewith.

Extractor 56 withdraws the cartridge or cartridge case from the chamber and ejection through an ejector slot 76 in the receiver ensues in the known plunger-type ejector manner.

What is identified as the breech bolt assembly includes breech bolt 28, locking bolt 30, ejector 48, ejector spring 50, ejector retaining pin 52, extractor 56, extractor spring 70, firing pin 42, and firing pin retaining pin 44.

Slide block 34 is distinguished by rear cam cuts 78 and forward cam cuts 75 on each of its sides, as shown in FIG. 7.

When breech bolt 28 and slide block 34 have reached their rearmost positions, the slide block is ready for movement forwardly and slide block rear cam cuts 78, after a small amount of free travel, contact the rear lower cam cuts on locking bolt 30 to cause the locking bolt and attached breech bolt to move forwardly therewith.

The breech bolt, during forward movement, strips topmost cartridge C from the magazine ears 80 of a magazine shell 82 and loads same into the chamber in known manner. As the breech bolt reaches forwardmost position, slide block rear cam cuts 78 cam the respective locking bolt cam ears 32 upwardly to force the locking portion of the locking bolt into receiver locking bolt slot 38.

The forward and rearward walls of receiver locking bolt slot 38 are each disposed at a slight angle relative to the vertical axis of locking bolt 30 and the front and rear of the recoil portions of the locking bolt are disposed at corresponding angles. The rearward wall 88 of slot 38 is delineated a recoil shoulder.

As the recoil portion of the locking bolt is moved upwardly in the receiver locking bolt slot, breech bolt 28 is cammed forwardly, giving additional leverage for cartridge seating. Conversely, as slide block 34 moves rearwardly to open the breech bolt, a corresponding leverage is exerted, aiding in extraction.

Longitudinally-extending, horizontally-disposed slots 90 on each side of the receiver complement mating tongues 92 on the slide block.

Slide block shelves 54 serve to support the breech bolt and conjointly with the top wall of the receiver, prevent unwanted vertical movement of the breech bolt. Unwanted lateral movement of the breech bolt is prevented by the upper walls of the split slide block and the walls of the receiver.

A plurality of slots 98 are in tongues 92 of the slide block and complemental openings are provided in the rear lower portion of the receiver.

The breech bolt assembly, sandwiched between the split slide block, is readily positioned in the receiver by pushing same upwardly through the complemental openings in the receiver.

Simultaneously, double action bars 100, permanently attached to or integral with the front end of the slide block and the rear end of a piston block 102, may be pushed upwardly into slots 104 in locking plate 12 so that the rear of breech bolt 28 is brought into proximity with the front of rear insert 14, and the rear of piston block 102 is brought into proximity with the front lower forwardly-facing portion of the locking plate.

The parts are thus in an extreme rearward position, during which slide block 34 is not supported by receiver since slide block tongues 92 are in alignment with the the complemental openings in the rear lower part of the receiver.

When the slide block is moved slightly forwardly of its rearmost position, the slide block tongues may then be supported in receiver slots 90 through the misalignment of slide block tongues 92 and receiver openings, a misalignment which is accomplished by interposing, after the slide block and breech bolts are in place, a buffer 106 (FIGS. 17 and 43), of nylon or other suitable material, so as to lie adjacent the forward face of the locking plate.

What is identified .as the slide block assembly includes bifurcated slide block 34, double action bars 100 (permanently attached to or integral with the slide block), piston block 102 (permanently attached to or held onto the action bars as by retaining clips), and a bolt handle 114 (permanently attached to the right hand action bar).

A suitable opening in the buffer receives a guide rod 108 therethrough. The guide rod is threadedly engaged in the locking plate and it supports the front end of the piston block and double action bars and slide block and provides for positive alignment of a gas piston 109 into its cylinder, as will appear.

As best seen in FIGS. 7 and 8, the buffer is held in continual contact with the forward face of locking plate 12 by a groove 110 in the lower surface of the locking plate which receives a complemental tongue 112 on the buffer.

Both handle 114 may be attached to or unitary with the right hand side of the split slide block (FIGS. 18, 32 and 33).

If desired, the manually-engageable portion of the bolt handle may be tubular in configuration (not shown) and a laterally-disposed pin could be placed within the tubular opening and retained by proper detents or other equivalent means. With the bolt handle in extreme rearward position, the pin could be pressed inwardly into a properly aligned opening in the outside of the receiver to retain the bolt in retracted position. To release the bolt from retracted position, the pin could be pulled outwardly.

As aforesaid, the forward ends of double action bars 100 may be unitary with piston block 102. Alternatively, they may be fixed to it as by brazing or welding or riveting or may be held relative thereto by means of tongues and grooves and retained in place by clips or equivalent.

During operation, the slide block is stopped in its rearward travel as the rear end of the piston block strikes the forward portion of the buffer 106.

The trigger-hammer-sear assembly will now be described, first with reference to FIG. 7 showing the firearm in a ready-to-fire position with a hammer cocked and .a trigger 122 in the forward position. A sear point 124 of a sear 126 is engaged in a sear notch 128 of the hammer. A trigger-sear pin 130 is at the bottom of an elongated slot 132 in the sear.

A reauwardly-disposed lug 136 on the forward midsection of trigger 122 is shown below an inset 138 in FIG. 7 at the forward lower section of scar 126.

The rounded ears of a double-armed trigger-sear spring 140 are retained in appropriate openings 142 in a trigger housing 144 by the inherent outward spring tension of a bend in the spring midsection (FIG. 28).

A sear arm 146 of the trigger-sear spring exerts downward and forward tension for urging a lower end of the sear downwardly and forwardly.

The lower extremity of scar arm 146 is retained in a suitable opening in the lower rear portion of the sear.

A trigger arm 150 of the trigger-sear spring exerts a forward tension on the lower part of the trigger for purposes of urging forwardly a finger part 154 of the trigger.

The lower extremity of trigger arm 150 is retained in a suitable opening in the lower rear portion of the trigger.

When the trigger is pulled in firearm discharge, trigger lug 136 contacts a lower-forward surface 158 of the sear to cause the sear to rotate clockwise and thereby to pull sear point 124 on the upper portion of the sear out of contact with sear notch 128 of hammer 120.

Immediately upon release of the hammer by the sear, the hammer, under the tension of a mousetrap type hammer spring 162, falls and strikes firing pin 42 and discharges the firearm. Meanwhile, the sear, being no longer under the influence of the superior tension of the hammer spring through the hammer, is now under the forward and downward tension of the weaker sear arm 146 of the trigger-sear spring. The scar moves downwardly along the trigger-sear pin and the lower portion moves slightly forwardly as trigger lug 136 enters sear inset 138.

Sear surface 158 is stopped by the inside rear portion of the trigger and downward movement is precluded by the upper portion of elongated slot 132 contacting the top surface of trigger-sear pin 130.

The parts are now in the FIG. 9 position, wherein the trigger is shown as being held in the rear position.

The slide block assembly now recoils rearwardly by means subsequently to be described.

The hammer is cocked and the empty shell is ejected. Breech bolt 28 stops in the rear position, when the rearmost portion of piston block 102 strikes buffer 106, as shown in FIG. 8.

As the hammer is cocked, scar notch 128 of the hammer passes over sear point 124 of the sear and the upper portion of the sear moves first forwardly and second rearwardly while trigger lug 136 maintains its position in sear inset 138.

In FIG. 8, the cocked hammer is shown in'a slightly overtraveled position, breech bolt 28 being in the rear position, and the trigger being held back. The sear point of the sear is within the sear notch of the hammer and trigger lug 136 is in sear inset 138. As the breech bolt is closed, and the sear notch of the hammer no longer overtravels the sear point, trigger lug 136 acts as a hook to hold the sear in the down position and the top portion of slot 132 of the sear remains in close proximity to trigger-sear pin 130.

The breech bolt is closed and the cartridge is stripped from the magazine and fed into the chamber in conventional manner.

With the breech bolt so closed, the operator releases the trigger which moves forwardly under tension of the trigger arm 150 of the trigger-sear spring. As the rearmost position of trigger lug 136 clears the forward lower portion of sear inset 138, the sear is unhooked from the trigger, and the hammer, under the stronger tension of hammer spring 162, moves slightly upwardly carrying the sear therewith and overcoming the resistance of the weaker sear arm 146 of trigger-sear spring 140.

Trigger-sear pin 130 is now at the bottom of slot 132 in sear 126. Trigger lug 136 is below sear inset 138 in the lower front portion of the scar and hammer 120 is held in cocked position by virtue of sear point 124 of the sear engaged in sear notch 128 of the hammer.

The parts are then again in the FIG. 7 position showing the weapon ready-to-be-fired. The action is in the closed position, the hammer is in the cocked position, the trigger is in the forward ready-to-fire position, and the bottom of the sear slot contacts the trigger-sear pin.

A hump 164 on the lower rear end of hammer 120 acts as a stop, should the hammer overtravel the breech bolt due to inertia while being cocked.

An arcuate surface 168 in the lower front portion of the hammer is of the same configuration as the upper forward part of the trigger guard with which it is flush when the hammer is in the down position, as shown in FIG. 9.

When the hammer is cocked, a circular portion of the hammer, rearwardly of arcuate surface 168, protrudes sufliciently below the surface of the upper forward portion of the trigger guard as to be exposed, thereby defining an indicator to show that the hammer is cocked, which portion may be colored, as for example, red, if desired.

The hammer is maintained centrally within trigger housing 144 by means of its lowermost portion being retained in a hammer guide slot 172 in the lower front portion of the trigger housing (FIG. 25).

A safety 178 (FIGS. 12 and 13) is constituted by a base 180, a pivot stud 182, and a thumb piece staked and/or brazed or welded into place. Alternatively, the entire safety may be made unitarily.

What. is identified as the trigger housing assembly includes trigger housing 144, trigger-sear pin 130, triggersear spring 140, hammer 120, trigger 122, sear 126, hammer pin 186, hammer spring 162 and safety 178.

A vertical safety pivot opening 184 is placed centrally 8 within trigger housing 144 rearwardly of a hammer pivot pin 186.

A front end 188 of the safety acts as a cam to cam a lower fiat surface 190 of the cocked hammer forwardly when the safety thumb piece is thrown from a leftward Fire position to a rightward Safe position.

The front portion of safety base 180, forwardly of the pivot pin may be offset downwardly, now shown, so that the cam surface of the safety may contact the lower flat surface of the hammer at a greater distance from the hammer pivot thereby giving greater leverage to the safety as it earns the hammer sear notch downwardly.

Also, the extreme rear end of the safety base may be lengthened and bent upwardly (not shown) and be of such configuration that when the safety is thrown from the Fire to the Safe position, a portion of the upwardly bent rear end will contact the forward surface of the trigger above the trigger-sear pin thereby preventing the trigger from being pulled.

The safety provides a greater margin of protection against accidental discharge than is found in firearms having safeties which merely block their triggers. Movement of the safety hereof from Fire to Safe positions withdraws the hammer sear notch from contact with the sear point and locks the hammer in the withdrawn position so that while the trigger may be pulled, the hammer cannot fall. Only when the safety is placed in Fire position will the gun be discharged if the trigger is pulled. However, if rearward pressure is applied to the trigger, while the safety is being thrown from Safe to Fire position, the hammer cannot fall to fire the rifle. To discharge the firearm, it is necessary to allow the trigger to move to its most forward position before being pulled to the rear.

As the lower fiat surface of the hammer is cammed forwardly, by safety front end 188, the hammer pivots on the hammer pivot pin and sear notch 128 of the hammer :moves downwardly out of contact with sear point 124 of the sear.

As the sear notch moves downwardly, sear arm 146 of trigger-sear spring is relieved of the superior tension of the hammer spring, through the hammer, and moves the sear downwardly along slot 132.

When the sear has reached its most downward position and trigger-sear pin 130 is at the top of slot 132, trigger lug 136 is opposite sear inset 138 so that, should the trigger be pulled rearwardly, the lug would enter the inset and no movement would be imparted to the sear.

Meanwhile, the sear notch of the hammer is in the overtraveled position with respect to the sear.

The hammer cannot fall because safety front end 188, when in Safe position, interposes a block at surface of the hammer (FIG. 11).

When the safety is thrown from Safe to Fire position, safety front end 188 is moved to the right and out of contact with surface 190 of the hammer, allowing the hammer to move slightly upwardly carrying with it the sear due to the superior spring tension of hammer spring 162, so that the parts assume the FIG. 7 position.

If the trigger is held to the rear while the safety is being thrown from Safe to Fire position, the hammer cannot fall to fire for the reason that safety front end 188 moves to the right and out of contact with surface 190 of the hammer to allow the hammer to move upwardly due to the tension of hammer spring 162.

The hammer moves upward slightly until sear notch 128 of hammer 120 contacts sear point 124 of sear 126. Further upward movement is precluded by trigger lug 136 contacting the lower portion of sear inset 138 to prevent further upward movement of the sear along the triggersear pin extendable through sear slot 132.

In this position, the hammer cannot fall as the sear notch of the hammer cannot be released from the sear point of the sear until the trigger is released and allowed to go forwardly so as to withdraw the trigger lug from the sear inset allowing the hammer to pivot upwardly and the sear to move upwardly along the trigger-sear pin until further upward movement is stopped by the contacting of the bottom of the sear slot on the trigger-sear pm.

The parts now being in the FIG. 7 position, the trigger may be pulled so as to fire the gun.

A rear horizontally-extending leg 194 of the hammer spring is bent normally on a horizontal plane and a pair of inverted U-shaped bends, left-hand bend 196 and a right-hand bend 198, serve as detent notches on a bent portion 200 of leg 194 (FIGS. 10 and 14).

An upwardly-extending hump 204 on safety base 180 serves as a detent to keep the safety in either Safe or Fire position.

When hump 204 is in left-hand bend 196 (as viewed from the butt of the gun), the safety is in the Fire position, as shown in FIGS. 10 and 14. When hump 204 is in the right-hand bend 198, the safety is in the Safe position.

A safety assembly slot 206 is provided centrally in trigger housing 144, just forwardly of the trigger-sear pin opening, whereby the safety may be assembled, before the assembly of the other parts within the trigger housing, by placing pivot stud 182 in the safety pivot opening and the safety thumb piece through the safety assembly slot (FIGS. 12, 13, and 26).

The safety, so assembled, is in a position midway between Safe and Fire positions.

When the safety is in either Safe or Fire position, the lower rear portion of the safety thumb piece is out of alignment with the rear end of the assembly slot and the safety cannot be moved upwardly out of position.

As the safety thumb piece passes midway between the Safe and Fire positions, it is held in place by the downward tension of hammer spring leg 194 and an opposite shorter leg 210 of the hammer spring (FIG. 10).

The safety cannot be thrown to Safe position, if the hammer is not cocked in its ready-to-fire position (FIG. 9).

A magazine catch 212 shown in FIGS. 30 and 31, has an upper forward bend 214 in its top portion which fits freely in a retaining slot 216 in a rear magazine well wall 218 of a magazine housing 222, the various parts of which are held together as by brazing or welding or riveting or the like. Same may be unitary, if desired.

A magazine catch lug 224 extends through a lug clearance cut 226 in the mid section of the rear magazine well wall.

A magazine catch spring 228 has downwardly-extending ends which fit into appropriate openings in the top of the rear magazine well wall and also fit loosely through properly aligned openings in forward bend 214 in magazine catch 212 (FIGS. 7, 8, 29 and 31).

A U-shaped portion 232 of magazine catch spring 228 bears on the rear of magazine catch 212 and provides forward tension thereto. A forward bend 236 in U-shaped portion 232 of the magazine catch spring, during assembly, is sprung into the upper rear portion of an opening in the magazine catch to prevent upward motion of the spring and thereby to retain the downwardly-extending ends of the magazine catch spring in their respective openings.

What is identified as the magazine housing assembly includes magazine housing 222, magazine catch 212 and magazine catch spring 228.

The tapered magazine shell 82, best seen in FIGS. 5, 6 and 8 consists of side walls 240, a front wall 242, a rear wall 244, and magazine ears 80.

A magazine spring and follower 248 are integral, all to the efi'ect of reducing the overall height of the magazine.

A front magazine stop 250 and a rear magazine stop 252 protrude outwardly from the front and rear walls respectively and serve as stops by contacting the lower portions of magazine housing 222 as the magazine reaches its uppermost position when placed in the gun.

A magazine retaining lug 256 protrudes outwardly and downwardly from front wall 242 of the magazine shell and the bottom portion contacts the bottom of a front magazine retaining slot 258 in the inner front well wall of the magazine well in housing 222.

Magazine catch lug 224 of magazine catch 212 moves rearwardly and then snaps forwardly into a rear magazine retaining slot 260 in rear wall 244 of the magazine as the magazine is pushed upwardly into the magazine well and stops 250 and 252 contact the bottom portion of the magazine housing.

The forward portion of a bend 262 of magazine catch lug 224 contacts the rear magazine wall at the rear lower portion of rear magazine retaining slot 260 and due to the aforesaid forward spring tension of magazine catch spring 228 pushes the magazine forward at which time magazine retaining lug 256 enters the front magazine retaining slot 258 until stopped by contact of the front magazine wall with the inside portion of the front magazine well wall of the magazine housing.

The magazine is now fully in place and may be removed from the firearm only by pulling rearwardly on the thumb piece portion of the magazine catch.

In FIG. 43, a cylinder block 266 is shown as being dove-tailed to barrel 8 but it may be held in place in any other suitable manner.

A gas vent 268 is drilled through cylinder block 266 and communicates with an aligned opening 270 through the lower portion of the barrel.

A screw plug 272 is receivable in the lower enlarged portion of gas vent 268 to seal off same, but may be removable to facilitate cleaning.

Piston block 102 is provided with an integral gas piston 109, earlier referred to, although it may be a separate threaded part and made of a superior material, if desired.

A forwardly facing wall 280 of gas piston 109 around guide rod 108 is provided with an annular concaved ring providing a pair of sharp edges which function as scrapers and assist in keeping the guide rod and the inside Wall of the cylinder free of carbon and fouling accumulation.

An annular gas deflector portion of piston block 102, immediately to the rear of gas piston portion 109, is concaved to deflect gases forwardly when the piston leaves the cylinder during operation.

Gas piston 109 is provided with a longitudinally-ex tending horizontally-disposed bore through which the forward end of guide rod 108 extends whereby piston block 102 slides freely relative to the guide rod.

A compressible detent spring clip 284 is a unit tary structure and is formed from spring wire or equivalent material and fits into a transversely extending slot through the forward end of the guide rod, as shown in FIG. 43. Upon assembly, it is compressible so as to be receivable in the slot of the guide rod and is held thereto by its own spring tension.

The forward extremities of double action bars 100, which extend forwardly of slide block 34 and through locking plate slots 104, are fastened to or integral with piston block 102, as aforesaid.

When the slide block is assembled in slots in the receiver, it effectively forms a slide block in a T slot. See FIGS. 18 and 19.

Any tendency of piston block 102 to rotate about guide rod 108 is precluded by the double action bars fitting in slots 104 in locking plate 12 and by breech bolt 28 sandwiched in slide block 34 in receiver 10, as shown in FIGS. 17 and 18.

A recoil means comprises a small diameter spring 288, wound right hand (or left hand, if desired) and a large diameter spring 290, wound the opposite hand from the winding of the small diameter spring.

By means of the two springs, a spring action, more 1 1 nearly like that of a. spring which is longer than space permits in this instance, is achieved.

By means thereof, I obtain a softer spring action and a more desirable scale to the spring while keeping down the fiber stress.

To assemble the parts attached to barrel 8 and receiver 10, the breech bolt assembly is placed between the inner sides of the slide block assembly with locking bolt ears 32 in the cam slots of the. slide block. The rear end of this assembly is pushed upwardly into the receiver through the assembly slots in the lower rear end of the receiver.

Meanwhile, the double action bars attached to the front end of the slide block are also pushed upwardly into suitable slots 104 in locking plate 12. Guide rod 108 is pushed through cylinder block 266 and into piston block 102.

The complete slide block assembly carrying the breech bolt assembly is then moved slightly forwardly to retain the slide block in the retainer grooves of the receiver.

Buffer 106 is placed in position with tongue 112 of the buffer fitting into groove 110 in the locking plate.

To assemble the springs into the firearm, same are disposed one inside the other and the guide rod is moved until the rear end is suificiently forward of buffer 106 to enable the springs to be bent slightly and to be pushed forwardly and compressed on the guide rod.

The guide rod is then pushed rearwardly through the opening in the buffer and threaded into the locking plate until detent spring clip 284 is brought into engagement with a series of radial detent cuts or notches (not shown) in the forward face of cylinder block 266.

Detent spring clip 284, contacting the notches, prevents the unscrewing of the guide rod during the shocks of semi-automatic firing.

Alternatively, a straight knurl 291 (FIG. 43) may be provided at the rear end of the guide rod to keep the guide rod from rotating during semi-automatic firing.

Final tightening of bedding screw 300, at final assembly, subsequently to be performed, serves to pull downwardly on the buffer and hence on the guide rod.

The magazine housing 222 and all parts attached thereto are now assembled to the receiver and its associated mechanisms.

A rear bent portion 292 of rear housing extension 294 of magazine housing 222 is now pushed upwardly and rearwardly in a housing extension opening 296 in the rear portion of the receiver. The lower portion of the rear housing extension opening being of sufficient depth to receive rear housing extension 294 during assembly.

When the extreme upper rear end of bent portion 292 of rear housing extension 294 strikes on the extreme rear of housing extension opening 296 to preclude further rearward movement of magazine housing 222, the front end of the magazine housing is pushed upwardly until an assembly lug 298 on the extreme upper forward end of the magazine housing is aligned with the assembly slot in the lower rear end of front insert 16 at which time the magazine housing is moved forwardly and the assembly lug enters the assembly slot. Further forward movement of the magazine housing is precluded by the extreme forward end of the magazine housing striking the lower rear end of the front insert.

The barrel-receiver assembly and all related parts including the magazine housing are placed in the stock.

Front bedding screw 300 is pushed upwardly through its appropriate opening and screwed in buffer 106 until the lower surface of the front insert is in contact with the front bedding surface of the stock.

A threaded steel insert, not shown, may be inserted in the buffer to provide substitute threads for the front bedding screw.

The assembly lug on magazine housing 222 is now retained in the assembly slot of the front insert since the extreme lower rear end of the rear housing extension of the magazine housing cannot move rearwardly sufiiciently ward movement of the housing.

to allow the assembly lug 298 to clear the assembly slot due to the proximity of the wood 301 of the stock at the rearmost end of the housing, all so as to effect retaining of the magazine housing loosely in place.

Trigger housing 144, with all parts assembled thereto, is pushed forwardly and upwardly into the lower rear portion of magazine housing 222 until front insets 302 on the trigger housing contact lugs 304 on the rearwardly bent portion of rear magazine well wall 218 of the magazine housing at which time the rear end of the trigger housing is pushed upwardly until the upper portion of a tang 306 of the trigger housing contacts a rear housing bedding surface of the stock. This precludes further up- The trigger-sear pin and hamer pivot pin are slip fits in their respective openings permitting easy removal without tools.

With the trigger housing assembled in the magazine housing, the pins are retained in place by the inside walls of the magazine housing.

A rear bedding screw 308 is pushed upwardly through a stock bushing 310 until the threaded portion thereof contacts threads in bent portion 292 of rear housing extension 294 whereupon it is screwed therein.

The assemblies or parts are simultaneously assembled into a single unit by a double camming action and a double locking action as the rear bedding screw is tightened.

The beveled portion of the screw head strikes an arcuate beveled surface 312 of trigger housing tang 306.

A stock clearance cut is of such configuration as to prevent the beveled surface of the screw head from contacting the wood rearwardly of the trigger housing tang.

Stock bushing 310 precludes unwanted movement of the screw.

Continued tightening of rear bedding screw 308 simultaneously forces the rear end of the trigger housing upwardly and earns it forwardly until the upper portion of tang 306 is in firm contact with the rear bedding surface of the stock and the trigger housing inset 302 is solidly locked on lugs 304 of the magazine housing.

Meanwhile, the rear bedding screw, being threadedly engaged in the opening of the bent portion 292 of rear housing extension 294 of the magazine housing, pulls the rear end of the magazine housing downwardly therewith.

As the bent portion of the rear housing extension is at a corresponding angle to a cam surface 314 in housing extension opening 296 in the rear portion of the receiver, the magazine housing, along with the trigger housing, is cammed forwardly until the front portion of the magazine housing is pressed solidly against the lower rear portion of front insert 16 to preclude further forward movement, assembly lug 298 being in the slot in the lower rear portion of the front insert as previously described.

Both housings are now locked solidly together and, in turn, are locked solidly to the receiver and rear bedding screw 308 has pulled the underside of the bent portion of the rear housing extension firmly against cam surface 314 in the housing extension opening in the receiver, which, in turn, as pulled a rear bedding surface 316 of the receiver into firm contact upon the rear receiver bedding surface of the upper portion of the stock.

The upper rear portion of trigger housing tang 306 bears solidly on the rear housing bedding surface in the lower portion of the stock.

In the above, the rear insert, brazed or welded or soldered or otherwise permanently attached to the receiver prior to streamlining, is designated as the rear portion of the receiver.

The front bedding screw is now finally tightened. The bedding surface of the front insert is down upon the front bedding surface of the stock and the top of the opening in buffer 106 in firm contact with the knurled portion of the guide rod.

The receiver, with the housings solidly locked thereto, is now locked solidly to the stock. Stated otherwise, the

receiver assembly, with the housing assemblies locked solidly thereto, is now locked solidly to the stock.

FIG. 42 shows the locking plate bearing on the recoil surfaces 318 of the stock.

The permanent assembly of the barrel to the receiver has, in effect, made the front insert a part of the receiver.

Fore end cover 6 is placed over the barrel and held in place by such means as retaining clips.

In operation, after cartridge C is fired and the bullet has passed the aligned gas vent openings, gas passes from the barrel therethrough under high pressure to the piston chamber and strikes the piston head the conventional sharp blow.

Thereby, a portion of the energy of the discharge of the firearm is transmitted to the piston and the recoil springs. After the inertia of the slide block assembly including the piston block, action bars, operating handle, and split slide block, has been overcome, rearward movement of the assembly is initiated.

The slide block assembly initially travels a short distance of pretravel. The pretravel distance may be varied or controlled during manufacture, as desired. This offers the bullet an opportunity to have left the muzzle whereby the chamber pressure is sufficiently reduced to facilitate easy extraction.

The slide block cams the locking bolt out of the locking bolt slot in the receiver. The breech bolt assembly comprises the breech bolt, locking bolt, firing pin, firing pin retaining pin, ejector, ejector spring, ejector retaining pin, extractor, and extractor spring. The breech bolt assembly and slide block assembly travel rearwardly in conventional manner by means of the force imparted to the front end of the piston by gas resulting from the explosion of the cartridge as is known.

The Weight of the slide block assembly being several times greater than the total weight of the breech bolt allows the former to hold its momentum as it carries the latter therewith to the rear after the piston has left the cylinder block.

During this period of rearward travel, the cartridge is ejected by the ejector, the hammer is cocked by the rear of the breech bolt, and the rear of the piston block strikes the buffer to stop the slide block and breech bolt assemblies in their rearrnost position.

The recoil springs meanwhile have been compressed.

During its forward travel, by means of the recoil springs releasing their tension, the breech bolt picks up a cartridge from the magazine and feeds it into the chamber of the barrel and the slide block earns the locking bolt in the locked position.

I claim:

1. In a firearm, the combination of, a barrel, a stock, a receiver, a cam surface on the receiver, a trigger housing, a cam surface on the trigger housing, a magazine housing, a rear bedding screw having a cam surface, a cam surface on the magazine housing, with the trigger housing and magazine housing being held in locked relationship to each other and to the receiver upon the tightening of the rear bedding screw against the cam surface of the trigger housing for effecting a simultaneous tightening of the cam surface on the magazine housing against the cam surface on the receiver.

2. In the firearm as set forth in claim 1 including, tongues on the magazine housing and grooves on the trigger housing for locked interengagement upon the tightening of the rear bedding screw into bearing relationship against the cam surface of the trigger housing.

3. In the firearm as set forth in claim 1 including, a horizontally-arranged slot on each side of the receiver and a plurality of spaced vertically-arranged slots on each side of the receiver, and a slide block having spaced tongues on each side thereof and mating with the respective vertically-arranged slots and slideable along the respective horizontally-arranged slot in the receiver.

4. A firearm including: a barrel, a stock, a receiver having a horizontally-arranged slot on each side thereof and a plurality of spaced vertically-arranged slots on each side thereof, a trigger housing, a magazine housing with camming means on the rear portion thereof, camming means on the rear portion of the receiver for mating with the magazine housing camming means, a locking plate, a piston block, a slide block having spaced tongues on each side thereof and mating with the respective vertically-arranged slots and slideable along the respective horizontally-arranged slot of the receiver, a buffer interposed between the front end of the locking plate and the rear end of the piston block following assembly of the slide block through the vertically-arranged slots in the receiver and with the buffer providing a stop means for precluding excessive rearward movement of the slide block and with the misalignment of the slots of the receiver and the tongues of the slide block providing a means for retaining the slide block within the receiver.

5. In the firearm as set forth in claim 4 including, a front bedding screw, an opening in the buffer, and a guide rod having a rear end extending through the opening in the buffer for locking the guide rod against rotation upon the tightening of the front bedding screw.

6. In a firearm, the combination of, a barrel, a stock, a receiver having camming means, a trigger housing having camming means, a magazine housing having camming means, a rear bedding screw, and tongues on the magazine housing and grooves on the trigger housing serving as locking means for interlocking the housings and the receiver together upon the tightening of the rear bedding screw upon the camming means of the receiver.

7. In the firearm as set forth in claim 6 including: an assembly lug on the forward end of the magazine housing, a slotted front insert positioned within the forward portion of thereceiver, the lug of the magazine housing being receivable in the slot of the front insert and locking the magazine housing to the front insert upon tightening of the rear bedding screw.

References Cited UNITED STATES PATENTS 1,069,339 8/1913 Layman 4275 1,996,124 4/1935 Rowley 4275 2,247,011 6/1941 Browning 42-75 2,945,423 7/1960 Allyn 42-75 B. A. BORCI-LELT, Primary Examiner. 

